SU1283741A1 - Optical keyboard - Google Patents

Abstract

The invention relates to computing and automation, namely, devices for manual entry of information, and can be used to create control panels, data terminals, and microcalculators. The purpose of the invention is to increase the reliability of the optical keyboard by increasing the modulation depth of the light flux. The optical keyboard contains a light source optically coupled by mutually orthogonal light guide channels with photodetectors. At the intersection of the light guide channels are located the key heads with a return spring and a rod, at the lower end of which a light flow modulator, having the shape of a cruciform prism, is fixed. Each channel is made in the form of successive trapezoidal prisms. In the initial state, the upper surface of the cruciform prism fits tightly to the lower surface of the light guide channels. The light from the source enters the light guide channel, then into the cruciform prism, which in this case is part of the light guide channel, then again into the channel, etc., then to the photodetector. When any key is pressed, the light flux modulator moves away from the lower surface of the corresponding channels. This breaks the continuity of the two light guide channels, i.e. leads to modulation of the signals of the corresponding photodetectors. The design of the luminous flux modulator in the form of a cruciform optically transparent prism allows switching the light in two mutually orthogonal light guide channels. 3 il. S S (L

Description

The invention relates to computing and automation, namely, devices for manual entry of information, and can be used in the creation of control panels, data terminals, and microcalculators.

The aim of the invention is to increase the reliability of the optical keyboard by increasing the modulation depth of the light flux.

FIG. 1 shows the construction of an optical keyboard; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows the structure of a light flux modulator.

The optical keyboard contains an optically transparent panel 1, rectangular depressions 2, mutually orthogonal light guide channels 3 isolated from each other, light sources 4, photodetectors 5, light flux modulators 6, keyboard heads with rod 7, return springs 8, surface 9 of panel 1 and the surface 10 of the modulator 6.

The optical keyboard works as follows.

In the initial position of the light guide

ten

15

20

25

When you press any of the keys, the modulator 6 moves away from the panel. The light flux is partly scattered from the front of panel 1 - and modulator 6 and arrives at the photodetector 5 strongly attenuated.

Due to the fact that the interruption of the luminous flux occurs in two mutually orthogonal directions, the signal at the corresponding photodetectors 5 is simultaneously recorded in two channels. In this way, any of the pressed keys is recognized.

The prepaired design of the optical keyboard is highly reliable, since when the keys are pressed, the corresponding light guide channels break. In the initial state, the light guide channels are non-illuminated, this prevents the channel from getting into the channel, dirt, moisture, and also protects from external illumination.

Claims (1)

Invention Formula Optical keyboard containing light sources optically coupled by mutually orthogonal light guide the cross section of the light guide channels are located keyboard heads with return springs and rods, at the ends of which are fixed light breakers The channels are inseparable. With the use of photodetectors, the transfer of an unbroken channel protects the light guide channels from exposure to heat, dirt, and moisture, while there is no influence of the light guide channels on each other. The luminous flux from a non-15 flux, which differs from the point 4 into the panel 1, reflected from the surface 9 of the panel, the luminous flux is directed to the modulator 6, reflected from the side surfaces 10 of the modulator, the flux returns to the panel and etc. As a result, the flow through the light-water channel 3 enters the photodetector 5, that, in order to increase reliability by increasing the modulation depth of the luminous flux, each fiber channel is made in the form of sequentially arranged trapezoid prisms, and the luminous flux interrupters are made in the form of cruciform prisms. When you press any of the keys, the modulator 6 moves away from the panel. The light flux is partly scattered from the front of the panel 1 - and modulator 6 and is fed to the photodetector 5 greatly attenuated. Due to the fact that the interruption of the luminous flux occurs in two mutually orthogonal directions, the signal at the corresponding photodetectors 5 is simultaneously recorded in two channels. In this way, any of the pressed keys is recognized. The prepaired design of the optical keyboard is highly reliable, since when the keys are pressed, the corresponding light guide channels break. In the initial state, the light guide channels are non-illuminated, this prevents the channel from getting into the channel, dirt, moisture, and also protects from external illumination. Invention Formula Optical keyboard containing light sources optically coupled by mutually orthogonal light guide channels with photodetectors, into a stream characterized by the cross section of the light guide channels are located keyboard heads with return springs and rods, at the ends of which are fixed light breakers channels with photodetectors, into a stream characterized by channels with photodetectors, into a stream characterized by that, in order to increase reliability by increasing the modulation depth of the luminous flux, each fiber channel is made in the form of sequentially arranged trapezoid prisms, and the luminous flux interrupters are made in the form of cruciform prisms. Oh FTs8. 2 h 7 PU8,3